WALNUT CREEK — Evelyn and Myron Herrell were surprised and saddened when they walked into Bonanza Street Books on Monday and saw a sign announcing the store will close in late March.

“I’m feeling so emotional,” Evelyn, 88, said to her 92-year-old husband as they shopped for books about Greek mythology for their granddaughter.

Like many of the independent bookstore’s faithful customers, the pair has shopped at the place for decades. But times are changing, as buyers choose books at chains such as Barnes & Noble, online at Amazon.com or at discount stores such as Costco.

“It’s a long-term trend that rent and other expenses have been going up while sales have been flat or going down,” said owner Peter Guadagni, who bought Bonanza Street Books eight years ago, after it had been operating downtown since 1987. “Reading is going down.”

In a report released last year, the National Endowment for the Arts found that Americans are spending less time reading and comprehension skills are diminishing, and that these declines affect America’s economy, culture, civic and social climates. Book sales peaked in 2000 with 1.6 billion units sold, then declined by 6 percent, or 100 million units, in the following six years, according to the report.

Bay Area bookstores have felt the crunch.

Diablo Books on Ygnacio Valley Road closed late last year after it could not afford rent increases in the Ygnacio Plaza shopping center. Cody’s in Berkeley, Bay Books in Pleasanton and Acorn Books along with a Black Oak Books location in San Francisco also have shut their doors in the past two years.

After Bonanza closes, Walnut Creek’s only used-book stores will be the small Hooked on Books shop in the Rossmoor shopping center and the Friends of the Library bookstore, which raises money to support downtown library programs. Lafayette Book Store manager Linda Grana said her independent shop is doing OK, but she is sorry to see Bonanza close.

“When I heard the other day I was just devastated,” Grana said. “I got tears in my eyes. I live in Walnut Creek and sometimes on my days off I’ll hang out at Bonanza because they have a real comfy, cozy reading area. They’ve been there forever. They’re like an icon in Walnut Creek.”

The city’s retail scene has changed since the establishment named “Best Indie Book Store in the East Bay” by Diablo Magazine for eight years in a row first opened. Guadagni, 52, said foot traffic at the store dropped off dramatically after August 2001, when the nearby Festival Cinema closed.

The following month, the Sept. 11 terrorist attacks sent economic ripples across the country.

People who used to spend hours scouring used bookstores to find rare books for their collections can now get what they’re looking for online. And the price of hardcover books has gone up so much in the past few years that customers previously willing to spend a few extra dollars to support independent bookstores now opt for lower prices at chain and discount stores.

Guadagni, who worked in software consulting before buying the store, said he is looking for work after the store closes. He predicts that even giants such as Barnes & Noble may face difficult times ahead, because their stores are expensive to operate.

In Walnut Creek, chains such as Bombay, Thomasville furniture, Dress Barn and Talbots Kids are going out of business.

“There’s no question that the economy is softening, and that’s evident in the retail business right now through announced store closures,” said Walnut Creek commercial real estate broker John Cumbelich. “It’s happening across an array of store types and store sizes. You can be high-end like Bombay or Talbots. You can be a mom and pop such as Bonanza Street. No one’s immune from the economy.”

Yet right across the street, the Walnut Creek Yacht Club has extended its lease and expanded and remodeled its restaurant, betting that it can attract and retain additional customers in the years to come. Chef Kevin Weinberg, who competes with chain restaurants in town, said he is sorry to see another independent business owner like Guadagni shut down.

“It’s a shame,” Weinberg said. “It’s a fantastic bookstore. He will be missed.”